Synopsis On 12 April 1991, at 1805, the Algerian-flag bulk carrier SERSOU and the Canadian-flag bulk carrier SILVER ISLE collided in the Chenal le Sainte-Thrse, a section of the St. Lawrence River ship channel within the limits of the port of Montreal. The collision occurred in daylight in relatively good visibility. No deaths, injuries, or environmental pollution resulted from the occurrence. Both vessels suffered heavy material damage. The Board determined that the SERSOU and the SILVER ISLE collided primarily because the SERSOU developed a swing such that she was heading across the track of the SILVER ISLE as the two vessels were meeting. A contributing factor was the demand by the pilot of the SILVER ISLE that the vessels change to a non-conventional starboard-to-starboard passing arrangement under conditions of uncertainty and confusion as to whether such passing arrangement was finally agreed to before the vessels were in a situation of extremis. The situation was further complicated when the master of the SILVER ISLE, called to the bridge late in the sequence of events, countermanded the orders of the pilot without having a full appreciation of the immediate situation and without notifying the SERSOU. 1.0 Factual Information 1.1 Particulars of the Vessels 1 Units of measurement in this report conform to International Maritime Organization (IMO) standards or, where there is no such standard, are expressed in the International System (SI) of units. 2 See Glossary for all abbreviations and acronyms. 3 All times are EDT (Coordinated Universal Time (UTC) minus four hours) unless otherwise stated. 4 Although the ship channel in this section of the river runs more north-south than east-west, it is the convention in the St. Lawrence River that the side of the river that would be on the port side of an upbound vessel is the south shore. 1.2 History of the Voyage At 17103 on 12 April 1991, the SERSOU, which was bound for Oran, Algeria, with a full cargo of grain, left the port of Montreal, Quebec, after receiving departure clearance from the Canadian Coast Guard (CCG). This special authorization, which was contingent on a specific minimum water level in the river between Montreal and Quebec City, was required because of the vessel's deep draught of 11.6 m. She was proceeding at half-speed, approximately eight knots (kn) through the water (10.5 kn over the ground), and, at 1745, she advised Montreal Vessel Traffic Services (VTS) that she was passing calling-in point (CIP) No. 25 off Pointe-aux-Trembles, Quebec, at the east end of Montreal Island. Meanwhile, approximately six miles downstream, the SILVER ISLE was upbound, in ballast, toward the Saint-Lambert Lock, en route to the Great Lakes. She was proceeding at her economical full speed, approximately 12.5 kn through the water against the 2.5 kn current (10 kn over the ground), and, at 1747, she advised Montreal VTS that she was passing CIP No. 24 off Cap Saint-Michel, Quebec. The vessels were in sight of each other and were closing at a combined speed of about 20.5 kn over the ground. At about 1803, the upbound SILVER ISLE was approaching the lower end of the Chenal le Sainte-Thrse, steering 195 (G) (gyro error nil). That course would take her close past buoy M140 on the north side of the channel4 at which point the two vessels would be about seven cables apart and on almost reciprocal courses. At about 1803, the downbound SERSOU was in the upper end and approximately on the centre line of the Chenal le Sainte-Thrse. There is contradictory evidence as to the intended course to be steered by the SERSOU. According to the officer of the watch (OOW) and the helmsman, the course was 034 (G), but the pilot stated that the vessel was steering 024 (G) (gyro error nil). The line of the channel is 021-201 and the intent was that the SERSOU would be allowed to gradually cross to the south side of the channel after making the small alteration of course of some 10 to port from the previous leg of the channel. There is contradictory evidence as to what occurred at this point. The pilot of the SERSOU and those in charge of the navigation on the SILVER ISLE testified that the SERSOU developed a sheer to port. The SERSOU was seen to begin a swing to port, or to extend an existing swing to port, such that she was heading toward the north side of the channel. The OOW and the helmsman of the SERSOU deny that there was a swing to port, but the pilot noted that the rudder angle indicator registered 15 to port. The pilot ordered the helmsman to put the wheel hard-a-starboard and, at 1803:40, alerted the SILVER ISLE to the action he was taking. It can be inferred from the evidence that the heading of the SERSOU at this time was sufficiently across the channel, toward the north side, so as to cause concern to both of the pilots and the navigation personnel on the SILVER ISLE. Because of the deep draught of the SERSOU and the limited clearance beneath her keel, the swing to port was not easily counteracted and the heading was not quickly corrected. At 1803:53, the pilot of the SILVER ISLE insisted to the pilot of the SERSOU that the vessels pass starboard-to-starboard instead of effecting the conventional port-to-port passing. The pilot of the SERSOU refused because he had already started to bring his vessel toward the starboard side of the channel. At 1804:03, the pilot of the SILVER ISLE again insisted for a starboard-to- starboard passing, and, at 1804:07, the pilot of the SERSOU agreed, based on his perception of the other vessel's aspect. He ordered thehelm of the SERSOU hard over to port. At this point, the SERSOU had stopped swinging to port and was starting to swing to starboard. She had the SILVER ISLE directly ahead, and the starboard side of the SILVER ISLE was partly open. The SILVER ISLE was in the vicinity of buoy M140 when the two vessels agreed to a starboard- to-starboard passing. Meanwhile, the OOW of the SILVER ISLE had advised the master, who was in his office, that he should come up to the bridge. The OOW then sounded the danger signal. When the master arrived on the bridge, he found the helm over to port, the SILVER ISLE swinging to port and the SERSOU at close quarters on his starboard bow. The SERSOU was two to three cables distant and slowly swinging to starboard toward the south side of the channel, across his vessel's path. As he believed his vessel to be in danger, he took over the conduct of the vessel from the pilot, ordered the wheel hard over to starboard, and sounded the general alarm. The SILVER ISLE gave no indication to the SERSOU, either by radio or sound signal, that the SILVER ISLE was altering course to starboard. As his vessel was now slowly beginning to swing to port in preparation for the agreed starboard-to-starboard passing, the pilot of the SERSOU was astounded to see the SILVER ISLE starting to turn to starboard. Accordingly, at 1804:23, he called the SILVER ISLE on the radio to ask for an explanation. The pilot of the SILVER ISLE replied that he was now going hard-a-port and ordered the helm hard over to port to lessen the angle of the impending impact. The two vessels put their main engines to full speed astern, but to little effect; a collision was inevitable at that point. First, the forepart of the SERSOU struck the port bow of the SILVER ISLE. As the two vessels passed each other, there was a second impact amidships and then a third one aft. The forecastle of the SERSOU heavily damaged three cabins and the crew's lounge on the SILVER ISLE. Following the collision, the master of the SILVER ISLE held his vessel's bow against the river bank for approximately six hours while inspection of the hull took place. The SERSOU continued on to Tracy, Quebec, for a hull inspection. 1.3 Injuries to Persons 1.4 Damage 1.4.1 Damage to the Vessels The SILVER ISLE sustained heavy damage on the port side forward, amidships and aft. The SERSOU also sustained heavy damage, but it was limited to the port bow. 1.4.2 Environmental Damage There was no pollution or other damage to the environment as a result of the collision. 1.5 Certification 1.5.1 Vessel Certification Both vessels were manned, certificated and equipped in accordance with existing regulations. 1.5.2 Personnel Certification The members of the crews of the SILVER ISLE and the SERSOU who were directly involved in this occurrence held the required certificates, and the pilots were appropriately licensed. 1.6 Personnel History 1.6.1 Masters The master of the SILVER ISLE had been going to sea since 1953, had been sailing as a master since 1978, and had been on the SILVER ISLE since the spring of 1991. The master of the SERSOU had been employed in a seafaring capacity since 1954, had been sailing as a master since 1972, and had been on the SERSOU as master for the last seven months. 1.6.2 Officers The OOW of the SILVER ISLE had been going to sea since 1959, had been sailing as a chief officer and a relieving master since 1988, and had been on the SILVER ISLE since the spring of 1991. The OOW of the SERSOU had been employed in a seafaring capacity since 1976, had been sailing as a chief officer since 1982, and had been on the SERSOU since 1990. 1.6.3 Pilots The pilot of the SILVER ISLE, a Class A pilot for 17 years, had been given the assignment some four hours before the arrival of the vessel at Pointe des Ormes, Quebec. He boarded at approximately 1230, and his destination was the Saint-Lambert Lock. The pilot of the SERSOU, a Class A pilot for 20 years, had been given his assignment four hours before the vessel's estimated departure time of 1630. He boarded the SERSOU at approximately 1500. Both pilots had had a rest period in accordance with Laurentian Pilotage Authority guidelines, that is, a minimum of 10 hours. 1.7 Weather and Current Information 1.7.1 Weather as Recorded by the Vessels The SERSOU recorded clear skies, five-mile visibility, no wind, calm sea and a temperature of 8C. The SILVER ISLE recorded clear skies, 15-mile visibility, south-west winds at five knots, calm sea and a temperature of 8C. 1.7.2 Current The tidal influence in this area is near zero and, therefore, was not a factor in the accident. South-east of le aux Vaches, Quebec, the current runs toward the north at an angle to the line of the channel. The current then turns toward the north-east in the area where the collision occurred, again at an angle to the line of the channel. The current was about 2.5 kn in the area in which the collision occurred. The water level was 2.9 m above chart datum, to a total depth of 13.6 m. 1.8 Navigation Equipment 1.8.1 Vessels' Equipment 1.8.1.1 Mechanical and Electrical Systems The propulsion and steering systems and all other machinery and equipment required by regulations on both vessels were in good working order and did not contribute to the collision. After the collision, a test of the rudder of the SERSOU was conducted while the vessel was at anchor. The rudder took about 14 seconds to go from hard-a-starboard (35 rudder) to hard-a-port with two pumps in operation. A similar test was carried out on the SILVER ISLE, but the time was not recorded. However, a time of 18 seconds is estimated for this type of vessel. The course recorder on the SERSOU was operational, but it was not switched on at the time of the collision. The time-logging mechanism on the engine data logger was not working. The Sat-Nav on the SERSOU had been set for a speed of eight knots before the vessel left Montreal. At the time of the collision, the Sat-Nav was registering an incorrect position downstream from the actual location. The SILVER ISLE was equipped with a course recorder, but it had not been used for some time. Without course recorder data relating to rudder angles and heading changes, the reconstruction of events before the collision can only be approximated. 1.8.1.2 Charts Both vessels carried the chart of the area that complied with the Charts and Publications Regulations; however, neither vessel was using it for reference or navigational purposes. The SILVER ISLE had Canadian Hydrographic Service (CHS) chart No. 1352, which covers the sector where the collision took place; however, the smaller-scale chart No. 1339 was being used. The SERSOU also had CHS chart No. 1352, but was using the British Admiralty chart No. 422, which is a small-scale marine chart generally used for voyage planning. 1.8.2 Shore Aids At the time of the collision, all buoys were in position, and no problems were reported with any of the shore navigation aids in the vicinity. 1.9 Radio Communications 1.9.1Inter-Ship During a radio communication at approximately 1747, the pilot of the SERSOU informed the pilot of the SILVER ISLE that the SERSOU went down to 11.6. Because of the imprecise language, the pilot of the SILVER ISLE interpreted 11.6 as being the other vessel's speed, whereas it actually was her draught. Voice recordings made by Montreal VTS indicate that a potentially dangerous situation had begun to develop by 1803:40, when the pilot of the SERSOU warned the SILVER ISLE by radio, to watch the SERSOU as the helm was hard over to starboard to counter the swing to port the vessel was experiencing. A transcript of the conversation reveals how the situation developed. 1803:40 SERSOU Watch me closely, I'm hard-a-starboard 1803:53 SILVER ISLEAre you OK to pass? Two whistles5 1803:59 SERSOU No, not two whistles, she's coming back 1804:03 SILVER ISLEIt's too late ... two whistles 1804:07 SERSOU OK, two whistles 1804:20 SERSOU Two whistles ... eh? 1804:21 SILVER ISLEWhat did you say? 1804:23 SERSOU What are you doing there, two whistles? 1804:25 SILVER ISLETwo whistles 1804:32 SERSOU I'm hard-a-port too 1804:54 SERSOU ... you told me ... you asked me to go to port. 5 In the International Regulations for Preventing Collisions at Sea (Collision Regulations), the manoeuvring signal for a vessel that is altering course to port is two short blasts on the vessel's whistle. In the lexicon of mariners, particularly on the Great Lakes, the expression two whistles has come to mean that the mariner will leave the other vessel on his starboard hand. At the time of this last call, the collision had either taken place or was just about to. The communications were carried out in French, the first language of both pilots. 1.9.2 Vessel Traffic Services (VTS) and Coastal Radio Stations The staff at the Montreal VTS Centre complied with operational procedures. Radio reception and transmission before, during and after the collision were normal. Montreal VTS did not attempt to contact the vessels because they were in sight of each other and communications between the two pilots were normal until just before the collision. 1.10 Emergency Equipment The master of the SILVER ISLE sounded the general alarm just before the collision. Neither vessel had to use any life-saving or fire-fighting equipment. 1.11 Composition of the Bridge Watch on the Two Vessels 1.11.1 SILVER ISLE The chief officer, who was the OOW, the pilot and a helmsman were present in the wheel- house of the SILVER ISLE. The master arrived on the bridge shortly before the collision. 1.11.2 SERSOU The chief officer, who was the OOW, the pilot and a helmsman were present in the wheel- house of the SERSOU. The master, who was in his office, was not summoned. 1.11.3 The Role of the Officer of the Watch (OOW) The CCG publication, Recommended Code of Nautical Procedures and Practices, states that the OOW is the master's representative and that his primary responsibility is the safe navigation of the ship. When a pilot is on board, the OOW has similar responsibilities. The OOW must also work closely with the pilot, but if there is any doubt as to the pilot's intentions, the OOW should seek clarification from the pilot. If the OOW still has doubts, he should notify the master immediately and take whatever action is necessary before the master arrives. 1.12 Pilotage 1.12.1 The Role of the Pilot In Canada, the Pilotage Act requires that, in a compulsory pilotage area, a licensed pilot or holder of a pilotage certificate shall have the conduct of any vessel subject to compulsory pilotage. Pilots have a detailed knowledge of the unique conditions that prevail in their areas. They are retained to direct the navigation of a vessel, particularly in confined waters and port approaches, and to expedite berthing and unberthing manoeuvres. The pilot is responsible to the master for the safe navigation of the vessel. However, the pilot has no other authority on board, and the master retains overall responsibility for the safety of his vessel. 1.13 Relieving the Pilot Section 26 of the Pilotage Act states that where the master ... believes ... that the actions of a licensed pilot ... are ... endangering the safety of the ship, the master may ... take the conduct of the ship from the licensed pilot. The Act continues, where the master of a ship takes the conduct ... from a licensed pilot ... the master shall file, within three days ... a written report setting out the master's reasons therefor with the Authority. The master of the SILVER ISLE relieved the pilot of the conduct of the vessel when he ordered starboard helm and countermanded the pilot's orders for the starboard-to-starboard passing arrangement. The master did not file the requisite written report with the pilotage authority. 1.14 The Role of Vessel Traffic Services (VTS) A marine traffic regulator may, under specific conditions, issue a direction to a ship with which the ship must comply (unless specific circumstances exist), but there is no intention on the part of the CCG to attempt to navigate or manoeuvre ships from a shore station. When the SERSOU called the SILVER ISLE at 1803:40, the staff at the Montreal VTS Centre started monitoring very closely the radar returns of the two vessels and continued to do so until the collision. The staff's observations made possible a reconstruction of the events. 1.15 Collision Regulations and Whistle Signals Approaching vessels normally pass each other port-to-port. Rule 9 of the Collision Regulations covers vessels proceeding in narrow channels and states, in part, that a vessel proceeding along ... a narrow channel ... shall keep ... to the ... limit of the channel ... which lies on her starboard side. In this case, a Canadian Modification to Rule 9 was significant. It states that the vessel proceeding with the current ... shall be the stand-on vessel and shall propose the place ... and ... side on which she intends to pass. Further, the vessel proceeding against the current ... shall keep out of the way ... and hold as necessary to permit safe passing. In this case, the SERSOU was the stand-on vessel. However, the pilot of the SILVER ISLE, although this vessel was the give-way vessel, insisted on a starboard-to-starboard passing arrangement to the pilot of the SERSOU. The two vessels altered their passing arrangement on the radiotelephone in accordance with a Canadian Modification to Rule 34 of the Collision Regulations. The modification states that vessels may use ... bridge-to-bridge radiotelephone instead of ... whistle signals to reach agreement in a meeting ... situation. Rule 34 of the Collision Regulations requires that when vessels are in sight of one another ... a vessel ... when manoeuvring ... shall indicate that manoeuvre by ... signals on her whistle. In this case, the SILVER ISLE did not sound a short blast to indicate that she was altering course to starboard when the master countermanded the pilot's order. 1.16 Personnel Communications Communications between the pilots were in French. The OOW of the SILVER ISLE did not understand French and, therefore, did not understand what passing arrangements had been agreed to. When the pilot informed him of the intention to pass starboard-to-starboard, the OOW summoned the master to the bridge. 1.17 Position of the Collision The exact position of the collision was not recorded by either vessel; however, other evidence indicates that it occurred slightly north of the centre line of the channel in the vicinity of the le Sainte-Thrse light. The channel is 244 m (800 feet) wide in this section, and there are no leading lights. After the collision, the master of the SILVER ISLE steered his vessel north and out of the channel to hold her upstream from the le Sainte-Thrse light pending an examination of the hull. The pilot was the only person on the SERSOU who knew that the collision had taken place in the vicinity of the le Sainte-Thrse light. The OOW thought that it had occurred in the vicinity of Cap Saint-Michel, based on the Sat-Nav estimated position which was further to the east as a result of the equipment's estimated speed input. 1.18Alteration of Course by the SILVER ISLE The times of the radio transmissions between the two pilots just before the collision were examined, with a view to establishing the timing of helm movements. This examination raised doubt as to whether the pilot of the SILVER ISLE had waited for an agreement with the pilot of the SERSOU before implementing his alteration of course to port to effect the starboard-to- starboard passing. 1.19 Headings of the Vessels and the Angle of Impact The precise headings of the vessels at the time of the collision are not known. However, the damage indicates that the initial impact occurred at an angle of between 20 and 30.